A new study published in the journal JAMA Pediatrics in April 2020 reports that children who use video games for more extended periods before the age of 5 years may be slightly fatter by the age of 14 if they also drink sugary drinks and have irregular bedtimes.
Study: Association of Video Game Use With Body Mass Index and Other Energy-Balance Behaviors in Children. Image Credit: Africa Studio / Shutterstock
What motivated the study?
Obesity among children is a looming and immense public health threat in the UK, as in other developed countries. More than one in three children in the US are overweight by the time they are out of primary school. Obesity owes its existence to excessive calorie intake compared to expenditure. A lack of physical activity and the intake of too much energy-dense food is responsible for this imbalance.
What do earlier studies show?
Several researchers have wondered how much the increasing use of video games contributes to this concerning trend. However, few studies show how video game use, as compared to general screen time, is related to body weight. One study on about 2800 children found that moderate video game playing was related to a higher weight, but not little or very high gaming. Another study carried out on adults playing video games found that males who played had a higher BMI compared to nonplayers. Another meta-analysis failed to find an association of higher body weight with video gaming, and later studies on adolescent body mass index vs. duration and frequency of video game use have also confirmed this finding.
Video gaming may also be linked to the increased consumption of snacks and sugary drinks, as well as reduced sleep and physical activity.
The current study aimed to explore this link, if it exists, and what factors contribute to it, such as sugary drinks, physical inactivity, irregular bedtimes and energy-dense foods. It is directed at exploring how BMI is linked to video game use over a more extended period of time. Such studies reflect how sedentary pursuits cause weight gain over the long term.
How was the study done?
The researchers used data from the Millenium Cohort Study, which represents children from all over the UK, born between September 1, 2000, and January 31, 2002. The data was collected from the caregivers at the time points of 5, 7, and 11 years. At 14 years, self-reporting was used instead. The scientists looked at the use of video games on weekdays, classifying them from into four categories, from none, through less than an hour, 1-3 hours, and three or more hours a day.
Television viewing was also classified into less than 3, and 3 or more hours a day, on weekdays.
Physical activity was measured in terms of the number of days when the children took part in a sports club or any class in which there was physical activity, from 1 to 6, representing five or more days a week and less than one day or none at all. Above the age of 14, children self-reported the average number of days per week in which they had moderate or vigorous physical activity, from 1 (every day) to none at all.
Regularity of bedtimes was also measured and classified as no or yes, based on the frequency with which they went to bed at the same time every day. The same was done with the consumption of sugary drinks and fatty foods.
The BMI was also calculated from the height and weight measurements taken at each of 5 visits during the Millenium Cohort Study. Race, gender and socioeconomic status were also used to adjust the results.
The study sample consisted of over 16,300 children, representing boys and girls equally. At ages 5 and 7, the associations between video game use and BMI were small but consistent. Again, they found that regular bedtime at age 7, sugary drinks at ages 7 and 11 years, physical activity at 7 years were all linked to video game use at age 5 and with a higher BMI at 14 years.
The fact that all the behaviors dealing with energy balance were associated at the age of 7 years led to the scientists exploring their possible role as mediators of the slight increase in BMI. However, only regular bedtime and the consumption of sugary drinks at the age of 7 years was found to be associated with video game use at five years, and with the BMI score at the age of 14 years.
Overall, the study found a significant association between video game use and BMI score, and about 37% of this was due to a combination of regular bedtimes and sugary drink consumption.
What does this study mean?
This is the first study to plainly explore how video game use and the BMI are linked, without including television screen time. The partial role played by regular bedtimes and sugary beverage intake is also evident. This agrees with older studies showing that these factors are linked.
The researchers suggest that children playing a lot of video games drink more sweet drinks because they view many embedded advertisements for these drinks, among other things. These can impress the implicit memory, which in turn links the brand advertised with the game, and builds the brand image over time. Sugary drinks are known to affect BMI.
Irregular bedtimes also affect BMI by shortening the sleep duration, increasing the total calorie intake. This is an explanation for the effect of video games before going to bed.
The small degree of change in BMI score makes it unlikely that these associations are of clinical use since earlier studies have suggested a cut off of 0.25 change in BMI SD score if it is to reduce the cardiovascular risk. The associations could be stronger at certain ages, reflecting increased play at older ages and perhaps more control over the food the child eats.
The implications of the study could extend more to preventing the effect of video games on bedtime regularity, and sugary beverage intake, than on explicitly establishing a link between video games and BMI as such. Policymakers and parents could reflect on how to break the exposure to sugary drink advertising by reducing the time spent on such games.
The study has its limitations, such as the possibility of the responses being directed by perceptions of social desirability, and the reliance on secondary rather than direct data collection. Nonetheless, it could help to frame better policies to make video games a tool to promote health in the children who are at most significant risk for obesity.
Goodman, W., et al. (2020). Association of Video Game Use with Body Mass Index and Other Energy-Balance Behaviors in Children. JAMA Pediatrics. doi:10.1001/jamapediatrics.2020.0202. https://jamanetwork.com/journals/jamapediatrics/fullarticle/2763827